A signal flashed from a mirror in his hand.
The auxiliary signal for N type signals is flashing red.
The pedestrian signal may flash that is safe to walk, but we still check left and right for the same reason.
The light signal above the telecaster flashed to life again.
It occurred in Manhattan, half an hour after the green-light signal had flashed.
At the same instant the green signal flashed on.
The signal flashed as the flags swirled down and up.
Some signal had flashed below when Harry tampered with the broken door.
Despite the fact that the orange signal was now flashing it remained stationary.
The red alert signals flashed like beacons in the night.